Department of Materials Science and Chemical Engineering, Kitakyushu National College of Technology, 5-20-1 Shii, Kokuraminami-ku, Kitakyushu, 802-0985, Japan.
World J Microbiol Biotechnol. 2012 Feb;28(2):677-86. doi: 10.1007/s11274-011-0862-8. Epub 2011 Aug 17.
The biogenic production of hydrogen sulfide is a serious problem associated with wastewater treatment. The aim of this study was to investigate the inhibitory effect of nitrate on the dynamics of sulfate-reducing bacteria (SRB) community in a laboratory-scale wastewater reactor, originating from a denitrifying plant using activated sludge. For this purpose, denaturing gradient gel electrophoresis (DGGE) analysis targeting the dsrB (dissimilatory sulfite reductase) gene was used in combination with chemical analyses and measurement of oxidation and reduction potential (ORP). The reactors were initially dosed with 1.0 and 4.0 g/L potassium nitrate and anaerobically incubated for 490 h. Addition of 4.0 g/L nitrate to the reactor was associated with a prolonged inhibition (over 300 h, i.e., 12.5 days) of sulfate reduction and this was consistent with a rapid decrease in ORP associated with nitrate depletion. The DGGE analysis revealed that nitrate addition remarkably attenuated a distinct group of dsrB related to Desulfovibrio, whereas other dsrB groups were not influenced. Furthermore, another sulfate reduction by Syntrophobacter in the later stages of the incubation period occurred in both reactors (regardless of the nitrate concentration), suggesting that different SRB groups are associated with sulfate reduction at different stages of the wastewater treatment process.
生物产生的硫化氢是与废水处理相关的一个严重问题。本研究的目的是调查硝酸盐对来自使用活性污泥的反硝化工厂的实验室规模废水反应器中硫酸盐还原菌（SRB）群落动力学的抑制作用。为此，使用针对 dsrB（异化亚硫酸盐还原酶）基因的变性梯度凝胶电泳（DGGE）分析与化学分析以及氧化还原电位（ORP）测量相结合。反应器最初以 1.0 和 4.0 g/L 硝酸钾投加，并在厌氧条件下孵育 490 h。向反应器中添加 4.0 g/L 硝酸盐会导致硫酸盐还原的长时间抑制（超过 300 h，即 12.5 天），这与与硝酸盐耗尽相关的 ORP 的快速下降一致。DGGE 分析表明，硝酸盐的添加显著减弱了与脱硫弧菌相关的一组特定的 dsrB，而其他 dsrB 组则不受影响。此外，在孵育后期，两种反应器中（无论硝酸盐浓度如何）都发生了另一种由Syntrophobacter 进行的硫酸盐还原，这表明不同的 SRB 组与废水处理过程的不同阶段的硫酸盐还原有关。
